1. Field of the Invention
This invention relates to an embroidery frame used to retain in tension region to be embroidered of a cloth on which embroidery is to be made by an embroidering machine.
2. Description of the Prior Art
The embroidery frame of this kind includes the following. A driving frame is adapted to be moved horizontally by a driving means in the embroidering machine. A cloth spreading frame is joined to the driving frame so that the cloth spreading frame projects horizontally from the driving frame. The cloth spreading frame is provided with an embroidery hole used to expose a region to be embroidered of a cloth thereto.
When this conventional embroidery frame is used, a small article, such as a sock can be embroidered without any trouble with the sock held on a cloth spreading frame so that a region to be embroidered thereof is positioned in the embroidery hole in the cloth spreading frame. However, in order to make embroidery on a wide region, such as the whole surface of the back of, for example, a sports jacket, it is necessary that a cloth spreading frame be formed to a larger size accordingly. In order that a larger-sized cloth spreading frame can follow up a horizontal movement of the driving frame without being vibrated laterally, it is necessary that the cloth spreading frame be made of a material of a large diameter and a material of a large thickness. If a cloth spreading frame is formed with such materials, the weight thereof increases. If embroidery is made on a cloth by using such a cloth spreading frame, a free end portion of the cloth spreading frame lowers due to its own weight. If the free end portion of the cloth spreading frame thus lowers, the lower surface of the region to be embroidered of a cloth rubs against a bed of the embroidering machine, so that the cloth wears out. In some cases, the region being embroidered of the cloth becomes unable to be moved in accordance with the movement of the driving frame due to the resistance occurring in the cloth rubbing against the bed of the embroidering machine, to cause a deformed embroidered pattern to be produced. These are the problems encountered in a conventional embroidery frame.
In order to prevent the free end portion of the cloth spreading frame from lowering as mentioned above, the cloth spreading frame may be formed with materials of a further larger diameter and a further larger thickness which permit the resultant cloth spreading frame to withstand its own weight. However, if the cloth spreading frame is formed in this manner, the weight thereof becomes very large. A heavy cloth spreading frame constitutes an unbalanced load with respect to the driving frame. This prevents a regular driving mechanism from providing a high-speed horizontal movement of the driving frame. A large and heavy cloth spreading frame has such problems.